Tuesday, June 9, 2015

Phasing DNA from siblings

I have now put into practise the methodology that David Pike used in the lecture that I attended. I am looking at 700,000 lines of data and I have placed the three sets of results side by side in an excel file. It can actually be quite speedy if you have the Chromosome Browser open as you can see where the long matching runs are. As it turns out one of my siblings is right at the limit of centimorgans between siblings (actually that is me) and quite a bit closer to my other sibling that has tested. I have completed 623 lines and have 123 sets (19.7%)  that I can not definitively phase into the columns that I have set up for my parents. I can always see one of them but the second one is an either or. The first one is easy because one of us has a doublet i.e. GG at that point so both of them have a G as an example or that could be A or C or T. But  one or both of us has AG and which means either parent could have AG or both of them could or one of them could have GG. My father was an only child and my mother had one brother who did not have any children thus limiting my ability to acquire information from others. I do have a second cousin in Canada though and I may ask if she would like to do FT DNA Family Finder. That would give me information on my Blake line. The lack of first cousins is certainly noticed when one is working on DNA! I also have second cousins in the States on my Buller line and I am thinking of trying to locate them and see if they would test. Persuading my other three siblings and the daughter of my deceased brother is another option and I will continue working away on that one. I think it could be very handy in the future to know the DNA of my parents.

I believe that we have now passed over a new watershed in genealogy. Prior to the last year or so genetics was just a new tool but now a year later I think it is a necessity in a project to really give it meaning.

I have one other set of data in the Chromosome Browser for a known 4th cousin who matches my siblings twice as much as I do and will watch for that as I am working away.

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